No, that's not a cover of a 70s-era psychedelic rock album. But if you were thinking "Dark Side of the Mushroom," you're closer than you think. This is a dark photo of a bioluminescent bunch of Mycena lucentipes mushrooms. They're an especially radiant species of the 65 different mushroom varieties known to glow.

Why does this tropical mushroom bother to put so much energy into lighting up the forest floor? Well, besides the survival value inherent in not being accidentally stepped on by mycologists crazy enough to trudge through the Amazon at night to search for them, a few theories have sprouted up. Researchers suggest that, like moths to a compact fluorescent bulb, the mushrooms attract all sorts of bugs. Considering that only a few bugs eat the mushrooms themselves, but that a lot of bugs eat the mushroom-eating bugs, it makes sense for the fungi to foot the energy bill for lighting an all-inclusive critter party. Also, breeze doesn't often find its way through dense jungle and so anything a mushroom can do to attract attention for the sake of spreading its spores round is advantageous.